Single-crystal growth and characterization of LiGaSe2

Single crystals of a new ternary lithium chalcogenide LiGaSe2 were grown by an improved directional solidification technique. The typical as-grown crystal has dimensions of about 4 mm cubed and shows a transparent light yellow color. We infer that LiGaSe2 crystallizes in the β-NaFeO2 structure having an orthorhombic unit cell (a = 6.833 Å, b = 8.227 Å, and c = 6.541 Å) by powder x-ray diffraction. The melting point was determined by differential thermal analysis to be 846 °C. The energy band gap of LiGaSe2 at room temperature was determined by optical reflectance measurements to be 3.65 eV.